单猪屎豆碱（Monocrotaline）的晶体结构

从猪屎豆种子中提取分离,得到单猪屎豆碱(Monocrotaline)。经X射线衍射分析测定了晶体结构。该化合物属正交品系,空间群为P2_12_12_1,晶体学参数:a=10.072(7),b=11.431(1),c=13.560(2)A,V=1561.3(7)A,Z=4,D=1.384g·cm~(-1) ,μ(MoKa)=0.699mm~(-1),F(000)=696,M=325.36,分子式为C_(16)H_(23)NO_6。在1≤3a(1)收集1627个衍射点,最终偏差因子R和R_0分别为0.058和0.05232。     

苍白秤钩风(Diploclisia Glaucescens)中的木脂素——左旋丁香脂素的晶体结构研究

通过X 射线单晶衍射法测定了标题化合物的晶体结构。结果表明 :晶体属正交晶系 ,P2 12 12 1空间群 ,a =8 6 0 10 (3) ,b =13 0 830 (9) ,c =18 1130 (11) ,V =2 0 38 2 0 (2 0 ) 3 ,Z =4 ,Mr =4 18 4 9,Dx =1 36 9g/cm3 ,λ(MoKα) =0 710 73 ,μ(MoKα) =1 12cm-1,F(0 0 0 ) =888。在 0 <2θ <5 0°范围内共收集了 1988个独立衍射点 ,其中可观测衍射点 196 3个 [Ⅰ≥ 8σ(Ⅰ ) ]。晶体结构用直接法解出 ,经全矩阵最小二乘法修正 ,最终偏离因子Rf=0 0 6 2 ,Rw=0 0 5 5。     

Eupenicillium sp.E-UN41产活性物质的分离与结构分析

在筛选微生物来源代谢产物的过程中,分离得到一株正青霉Eupenicillium sp.E-UN41,发酵液经离子交换树脂和葡聚糖凝胶等方法分离得到化合物UN41A.通过核磁共振波谱和X-单晶衍射进行该化合物的分子构型和晶体结构分析,确定其为4-氨甲酰基-1-β-D-呋喃核糖-5-羟基咪唑,与咪唑立宾同质.晶体属斜方晶系,空间群P212121,晶胞参数a=7.4897(7),b=11.3801 (15),c=14.0090(13)(A),V=1194.0(2) (A)3,Z=4,Dc=1.553g/m3,F(000) =592.晶体结构分析表明,分子中存在咪唑环共平面.     

Isolation and crystal ctructure of sulfur from Capparis spinosa fruits

从刺山柑果实中首次分离纯化得到S8单质.经X-射线单晶衍射分析,确认该化合物为S8晶体,M=256.48.晶体属斜方晶系,空间群Fddd.晶胞参数a=10.456(7)A°,b=12.908(9)A°,c=24.483(17)A°,V=3305(4)A°3,Z=16,F(000)=2048,R1=0.0915,wR2=0.1820.     

抗肿瘤活性化合物谷氨酰胺衍生物研究Ⅱ.N~2-苯磺酰基-L-谷氨酰胺的合成及其晶体结构研究

将L-谷氨酰胺与苯磺酰氯缩合,合成了与抗瘤酮A_(10)(3-苯乙酰氨基-2,6-哌啶二酮)的水解产物相类似的标题化合物。采用X-射线单晶衍射分析法研究了它的晶体结构。标题化合物分子式C_(11)H_(14)N_2O_5S,Mr=286.30,晶胞参数:a=5.373(2)A,b=15.073(1)A,c=16.277(3)A;α=89.99(1)~0,β=90.00(2)~0,γ=89.96(2)~0;正交晶系,空间群P2_12_12_1,V=1318.3A~3,Z=4,D_c=1.442g/cm~3,最终晶体学偏差因子R=0.031。     

几种重楼的染色体核型研究

作者对重楼属(Paris)的几个种:球药隔重楼(P.fargesii),毛重楼(P.mairei),花叶重搂(P.marmorata),黑籽重楼(P.thibetica),海南重楼(P.dunniana),巴山重搂(P.bashanensis),以及多叶重楼(P.polyphylla)的两个变种狭叶重楼(var.stenophylla)和华重楼(var.chinensis)的染色体核型进行了研究,发现种间及种内不同居群(population)间的核型都存在不同程度的差别。核型简式为:球药隔重楼K(2n)=2x=10=6m+2t(SAT)+2t+3bs,毛重楼K(2n)=2x=10=6m+4t+1bs,花叶重楼K(2n)=2x=10=6m+4t,黑籽重楼K(2n)=2x=10=2m+4m(SAT)+4t,海南重楼K(2n)=2X=10=6m+2t(SAT)+2t,巴山重楼K(2n)=2x=10=6m+4st,狭叶重楼K(2n)=2x=10=6m+1st+3t,华重楼K(2n)=2x=10=6m+4t。     

葱属植物物种生物学研究：Ⅰ.葱属6种材料的核型研究

分析了葱属(Allium L.)5个种6个居群的细胞学特征。这些种是太白韭(A.prattii C.H.Wright apud Forb.et Hemsl.),该种包括两个居群(Ⅰ、Ⅱ)。居群Ⅰ:K(2n)=2x=16=9m+1m(SAT)+4sm+2st,居群Ⅱ:K(2n)=2x=16=10m+5sm+1sm(SAT);天蒜(A.PaePalanthoides Airy-Shaw):K(2n)=2x=16=14m+2sm+3B;多叶韭(A.Plurifoliatum Rendle):K(2n)=2x=16=14m+2sm+1B;合被韭(A.tubiflorum Rendle):K(2n)=2x=16=12m+2m(SAT)+2sm;峨眉韭(A.omeiense Z.Y.Zhu):K(2n)=2x=22=2m+18sm+2T(SAT)。所研究的6批材料均为二倍体,除合被韭的核型为“1A”型,蛾眉韭的核型为“3A”型外,其余4批材料的核型均为“2A”型。其中峨眉韭和多叶韭的染色体数目为首次报道,天蒜和多叶韭的细胞中首次发现B染色体,并对其相互关系进行了探讨。     

百合属4种植物的核型研究

采用常规压片法对4种百合属植物野百合(L.brow n ii F.E.B row n ex M ie llez.)、兰州百合(L.d av id iiDuchartre var.un icolor(Hoog.)Co Hon.)、川百合(L.d av id ii Duchartre)、湖北百合(L.henry i B aker)进行了核型研究.结果表明,4种百合的染色体数目均为2n=24,核型除川百合为3A外,其余3种均为3B型.核型公式分别为:野百合2n(2x)=24=4m(2SAT) 2sm(2SAT) 4st 14t,兰州百合2n(2x)=24=2m(2SAT) 2sm 10st(2SAT) 8t 2T,川百合2n(2x)=24=2m(2SAT) 2sm 12st(3SAT) 8t,湖北百合2n(2x)=24=4m 18st 2t,其中湖北百合染色体核型为首次报道.通过比较发现,兰州百合与川百合的核型最为相似,亲缘关系相近;核型不对称性为兰州百合>川百合>野百合>湖北百合,以湖北百合的核型较为原始.     

北京东灵山地区植物群落多样性研究——种-面积曲线的拟合与评价

本文选择了 1 0条曲线作为种 -面积曲线的拟合模型 ,它们分别是S=b a A (1 )S=b aln A (2 )S=(b aln A) c (3)S=aln(A 1 ) (4)S=aln(b A 1 ) (5)S=a Ab (6)S=a A/ (1 b A) (7)S=c/ (1 ae-b A ) (8)S=c - ae-b A (9)S=a(1 - e-b A ) (1 0 )对其中的 7个非线性模型给出了参数初值的计算方法 ,并用 Gauss- Newton或 Marquardt方法计算非线性最优解。又选择了剩余标准差 (RSE)、相关指数 (CRI)、偏差绝对值的平均值 (AAD)和相对偏差绝对值的平均值 (AARD)作为模型拟合优劣的 4个评价指标。研究结果表明 :1 ) 7个非线性模型中参数初值的计算方法是可行的。从 4个评价指标来看 ,它们的非线性最小二乘解都明显优于线性最小二乘解 ;2 ) 1 0个模型的拟合效果都相当好 ,对 5个样地及其各层拟合的共 2 0 0个 CRI中有 71 .5%大于 0 .9,89%大于0 .8,其中曲线 (3)和 (9)最好 ,其次是 (5)、(6)、(2 ) ,(1 )和 (1 0 )最差 ;3)秩相关分析表明 ,3个评价指标RSE、AAD和 AARD相互之间存在极强的正秩相关 ,因此在本研究中 ,它们的评价结果具很强的一致性。     

我国八种蜜环菌的木腐特性

为了揭示我国不同蜜环菌Armillaria的木腐特性,本研究以我国8个蜜环菌种为材料,采用蜜环菌液接种1 cm³的枹栎Quercus serrata木方,置于23℃下培养60 d和120 d,采用重量法、Klason法、硫酸水解法和盐酸水解法测定木材质量、纤维素含量、木质素含量和半纤维素含量,研究各蜜环菌株的木腐能力及差异性。结果表明,各蜜环菌种对枹栎木质量损失率排序为:CBS M(A.borealis)>CBS A(A.sinapina)=CBS J(A.qinii)=CBS H(A.bruneocystidia)=CBS F(A.sinensis)=CBS B(A.gallica)>CBS N(A.violacea)=CBS D(A.ostoyae);木质素的分解能力排序为:CBS M=CBS A=CBS J>CBS H=CBS B=CBS F>CBS N>CBS D;纤维素降解利用率排序为CBS H=CBS A>CBS B>CBS J>CBS F>CBS D>CBS M>CBS N;半纤维素分...     

The Structure of Neplanocin C

Abstract

The molecular and crystal structure of neplanocin C(3), C₁₁H₁₃N₅O₄ M.W. = 279.26, has been determined by X-ray anlys?s. The space group is P2₁ with a=16.381(2), b=8.210(1), c=9.127(1) Å, β=105.31(1)° and z=4. The structure was solved by direct method, and least-squares refinement using 2093 reflections with |Fo|>3σ(F) led to the final R value of 0.0772. The sugar puckering of the two crystal-lographically independent molecules is C(2′)-exo-C(3′)-endo, and the torsion angles about the N(9)-C(1′) bond are 22.8(6) and 28.7(6)°, respectively (anti conformation).     

Crystal structure of beta-D-galactopyranosylamine

The crystal structure of beta-D-galactopyranosylamine (C6H13O5N) is orthorhombic, with space group P2(1)2(1)2(1), and cell dimensions a = 7.703(2), b = 7.788(2), c = 12.645(3) A, V = 757.612 A3, Z = 4; Dc and Dm are 1.573 and 1.587 cm-3, respectively. Using MoK alpha radiation (lambda = 0.7107 A), 2841 reflections were measured on a CAD-4 diffractometer. The structure was solved by using MULTAN-78, and refined anisotropically for the non-hydrogen positional and thermal parameters. Final agreement indices are R(F) = 0.074, wR(F) = 0.086, and S = 2.1523. The conformation is 4C1(D). The orientation of the primary alcohol group is gauche/trans. An unexpected feature of the hydrogen bonding is that the amino group accepts a strong O-H---N bond, but has no donor functionality in the crystal structure.     

Structure of fully hydrated fluid phase DMPC and DLPC lipid bilayers using X-ray scattering from oriented multilamellar arrays and from unilamellar vesicles

Quantitative structures of the fully hydrated fluid phases of dimyristoylphosphatidylcholine (DMPC) and dilauroylphosphatidylcholine (DLPC) were obtained at 30 degrees C. Data for the relative form factors F(q(z)) for DMPC were obtained using a combination of four methods. 1), Volumetric data provided F(0). 2), Diffuse x-ray scattering from oriented stacks of bilayers provided relative form factors |F(q(z))| for high q(z), 0.22 < q(z) < 0.8 A(-1). 3), X-ray scattering from extruded unilamellar vesicles with diameter 600 A provided |F(q(z))| for low q(z), 0.1 < q(z) < 0.3 A(-1). 4), Previous measurements using a liquid crystallographic x-ray method provided |F(2 pi h/D)| for h = 1 and 2 for a range of nearly fully hydrated D-spacings. The data from method 4 overlap and validate the new unilamellar vesicles data for DMPC, so method 4 is not required for DLPC or future studies. We used hybrid electron density models to obtain structural results from these form factors. Comparison of the model electron density profiles with that of gel phase DMPC provides areas per lipid A, 60.6 +/- 0.5 A(2) for DMPC and 63.2 +/- 0.5 A(2) for DLPC. Constraints on the model provided by volume measurements and component volumes obtained from simulations put the electron density profiles rho(z) and the corresponding form factors F(q(z)) on absolute scales. Various thicknesses, such as the hydrophobic thickness and the steric thickness, are obtained and compared to literature values.     

刺山柑果实中硫单质的分离与晶体结构

从刺山柑果实中首次分离纯化得到S8单质。经X-射线单晶衍射分析,确认该化合物为S8晶体,M=256.48。晶体属斜方晶系,空间群Fddd。晶胞参数a=10.456(7),b=12.908(9),c=24.483(17),V=3305(4)3,Z=16,F(000)=2048,R1=0.0915,wR2=0.1820。     

The crystal structure of isopropyl 1-thio-beta-D-galactopyranoside monohydrate at 123 K

The crystal structure of isopropyl 1-thio-beta-D-galactopyranoside monohydrate is orthorhombic, P2(1)2(1)2(1), Z = 4, with cell dimensions at 123 K [293 K] of a = 7.983(1) [8.037(1)], b = 24.574(5) [24.709(4)], c = 6.329(1) [6.3736(8)] A, V = 1241.84 [1265.71] A3. The calculated and measured density is Dx = 1.371 [1.345] g cm-3, Dm = [1.340] g cm-3. Diffraction data were obtained with CuK alpha radiation and a Nonius CAD-4 diffractometer. The structure was solved by using MULTAN, and refined to R(F2) = 0.051, RW(F2) = 0.078, R(F) = 0.029, S = 1.16 for 1502 reflections. The molecule has the 4C1(D) conformation. The orientation of the primary alcohol group is gauche/trans, and that about the glycosidic C-S bond is (-)synclinal relative to the ring C-O bond. Although this compound does not form thermotropic liquid crystals, it has two crystal-to-crystal phase-transitions, at 70 and 104 degrees, prior to melting at 126 degrees. The crystal structure has a characteristic, amphiphilic, head-to-head bilayer molecular packing, with intercalated alkyl groups. The water molecule is included in the hydrogen-bond structure that links the galactoside moieties.     

Synthesis and structure determination of some platinum (II) complexes with hydrophilic carboxylated tertiary phosphine ligands

[Pt(COD)Cl₂] (1) reacts with PPh₂(C₆H₄COOH) (2a,b,c), PPh₂(C₆H₄COONa) (2d), PPh(C₆H₄COOH)₂ (4b,c) and P(C₆H₄COOH)₃ (6b,c) with formation of the corresponding complexes [Pt(L)₂Cl₂] (3a,b,c,d, 5b,c, 7b,c). Halide abstraction from 3a by Ag⁺ promotes coordination of the ortho-carboxylate function to platinum, yielding [ -2)}{PPh₂(C₆H₄COOH-2)}Cl] (bd8) and [ovbar|{PPh₂(C₆H₄COO-2)}₂] (bd9). Reaction of 1 with CO and 2a or 2b gives [Pt(CO)(L)Cl₂] (10a,b), wherea 1 and 2,3-bis(diphenylphosphino) maleic anhydride yields

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(bd12) and [Pt{Ph₂PC(COOH)=C(COOMe)-PPh₂}Cl₂] (13). The ¹H, ¹³C and ³¹P NMR spectra are reported and discussed. The X-ray structural analysis of 3b showed the compound to be monoclinic, space group P2₁/n, Z=4, with a=1038.5(3), B=1792.6(4), C=2311.5(4) pm, β=91.6(2)° and D_calc=1.353 g cm⁻³. The structure was solved from 4832 observed reflections with F₀ > 4 σ(F₀) and refined to a final R value of 0.0743. The Pt atom is surrounded by two Cl and two P atoms in a square planar arrangement.     

X-ray crystallographic conformational study of 5'-O-[N-(L-alanyl)-sulfamoyl]adenosine, a substrate analogue for alanyl-tRNA synthetase

In order to elucidate the substrate specificity of alanyl-tRNA synthetase, 5'-O-[N-(L-alanyl)sulfamoyl]adenosine (Ala-SA), an analogue of alanyl-AMP, was chemically synthesized. Its binding ability is similar to that of the substrate based on the inhibitory activity for the aminoacylation of alanyl-tRNA synthetase. Taking advantage of the stable sulfamoyl bond of Ala-Sa, compared with the highly labile aminoacyl bond of alanyl-AMP, the molecular conformation of the former inhibitor was studied by X-ray single crystal analysis. Crystal data are as follows: C13H19N7O7S.2H2O, space group C2, a = 39.620(6), b = 5.757(1), c = 20.040(3) A, beta = 117.2(1) degrees, V = 4065(9) A3, Z = 8, and final R = 0.065 for 2785 independent reflections of F(2)0 greater than or equal to 2 sigma (F0)2. In the crystal, the molecule is in a zwitterionic state with the terminal amino group protonated and sulfamoyl group deprotonated, and takes an open conformation, where the L-alanine moiety is located far from the adenosine moiety with gauche/trans and trans orientations about the exocyclic C(4')-C(5') and C(5')-O(5') bonds, respectively. The conformation of the adenosine moiety is anti for the glycosyl bond and C(3')-endo for the ribose puckering, and alanine is in the usually observed trans region for the psi torsion angle. The molecular dimensions of the sulfamoyl group are nearly the same as those of the phosphate group. The biological significance of the observed Ala-SA conformation is discussed in relation with the molecular conformation of tyrosyl-AMP complexed with tyrosyl-tRNA synthetase.     

The crystal and molecular structures of lithium trimethylenediaminetetraacetatoferrate(III) trihydrate Li[Fe(trdta)]·3H2O and sodium ethylenediamine-N,N′-diacetato-N,N′-di-3-propionatoferrate(II) pentahydrate Na[Fe(eddda)]·5H2O

The crystal structures of Li[Fe(trtda)]·3H₂O and Na[Fe(eddda)]·5H₂O (trtda = trimethylenediaminetetraacetate and eddda = ethylenediamine-N,N′-diacetate-N,N′-di-3-propionate) have been determined by single crystal X-ray diffraction techniques. The former crystal was monoclinic with the space group P2₁/n,a = 17.775(3),b = 10.261(1),c = 8.883(2)Å, β = 95.86(4)° and Z = 4. The latter was also monoclinic with the space group P2₁/n,a = 6.894(2),b = 20.710(6),c = 13.966(3)Å, β = 101.44(2)° and Z = 4. Both complex anions were found to adopt an octahedral six-coordinated structure with all of six ligand atoms of trdta⁴⁻ or eddda⁴⁻ coordinated to the Fe(III) ion, unlike the corresponding edta⁴⁻ complex which is usually seven-coordinate with the seventh coordination site occupied by H₂O. Of the three geometrical isomers possible for the eddda complex, the trans(O₅) isomer was actually found in the latter crystal. Factors determining the structural types of metal–edta complexes are discussed in detail.     

Apolar peptide models for conformational heterogeneity, hydration, and packing of polypeptide helices: crystal structure of hepta- and octapeptides containing alpha-aminoisobutyric acid

The crystal structures of two helical peptides Boc-Val-Ala-Leu-Aib-Val-ala-Leu-OMe (VALU-7) and Boc-Val-Ala-Leu-Aib-Val-Ala-Leu-Aib-OMe (VALU-8) have been determined to a resolution of 1.0 and 0.9 A, respectively. Both the seven and eight residue peptides crystallize with two conformers per asymmetric unit. The VALU-8 conformers are completely helical and differ only at the C-terminus by a sign reversal of the phi, psi angles of the last residue. One of the VALU-7 conformers occurs as a normal alpha-helix, whereas in the other, the N(7)--O(3) alpha-type hydrogen bond is ruptured by the entry of a water molecule (W) into the helix, which in turn makes hydrogen bonds N(7)...W = 2.97 A and W...O(3) = 2.77 A. The other side of the water molecule is surrounded by a hydrophobic pocket. These two conformers give a static representation of a step in a possible helix unwinding or folding process. In the VALU-8 crystal the helices aggregate in a parallel mode, whereas the aggregation is anti-parallel in the VALU-7 crystal. The crystal parameters are VALU-7, P2(1), a = 10.203 (3) A, b = 19.744 (6) A, c = 22.561 (6) A, beta = 96.76 degrees, Z = 4, C38H69N7O10.0.5H2O, R = 6.65% for 3674 reflections observed greater than 3 sigma (F); and VALU-8, P2(1), a = 10.593 (4) A, b = 27.57 (6) A, c = 17.745 (5) A, beta = 95.76 (3) degrees, Z = 4, C42H76N8O11.0.25 CH3OH, R = 6.63% for 4701 reflections observed greater than 3 sigma (F).